Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are present, so the description carries full burden. It discloses read-only behavior ('not a product mutation', 'read-only'), output format ('Returns {events: [{event_name, metrics: [...]}, ...], product_id}'), and tenant scoping ('TikTok tenant-scoped read contract'). It does not mention potential limitations like pagination, but for a read tool that is acceptable.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured: purpose first, then safety, then output, then required parameter, then example. Every sentence adds value—no filler. The line breaks and explicit REQUIRED/EXAMPLE sections make it easy to parse.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With one parameter, no output schema, and no annotations, the description provides everything: purpose, usage context, parameter format, output shape, and a call example. Nothing an agent needs to correctly invoke this tool is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema only says product_id is a string. The description adds critical meaning: 'REQUIRED: product_id (str — UUID from products_list).' This tells the agent the exact format and source, which is essential for correct invocation. Given schema coverage is 0%, the description fully compensates.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Return AppsFlyer MMP event candidates for one product.' It clearly distinguishes this from mutations by stating 'This is metadata discovery, not a product mutation.' and adds tenant-scoped context, making it unambiguous among many sibling tools.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context: it's a read-only metadata operation requiring a product_id from products_list. It does not explicitly name alternatives or say 'use when not', but it implies usage by stating the read-only nature and that product-card edits are outside MCP. That is clear context without explicit exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.